(1) Field of the Invention
The present invention generally relates to a drum washing machine. More particularly, it relates to a balancing device for a drum washing machine realized as annular-shaped races that are provided to both sides of the washing machine's spin basket, and movable bodies seated in each race for the purpose of dynamically counteracting imbalances of the spin basket occurring during washing/dehydrating operation.
(2) Description of the Prior Art
A conventional drum washing machine is an electronic appliance that washes clothes using suds generated by the rotation of its drum-shaped spin basket. In the conventional drum washing machine, washing, rinsing and hydro-extracting tasks are automatically carried out according to a predetermined program. After the washing and rinsing of the clothes are finished, excess water is removed from the clothes by centrifugal force created by the spin basket rotating at high speeds during the dehydrating process. Abnormal vibrations and noise may be produced by the clothes not being evenly arranged in the spin basket during the dehydrating process. Consequently, a balancing device is essential for a drum washing machine to operate properly.
FIG. 3 depicts the construction of a conventional drum washing machine.
Referring to FIG. 3, the drum washing machine includes a housing 1, a tub 2 suspended by suspension springs 4a and shock-absorbing members 4b in the housing 1, and a spin basket 3 rotatably installed in the tub 2. The spin basket 3, which is rotated by an electric motor 5 installed on the bottom of the housing 1, includes a plurality of small holes 3a formed on all of its surfaces, and a plurality of lifters 3b protruded inward.
Water that is removed from clothes in the spin basket 3 by centrifugal force flows into the tub 2 through these small holes 3a, and lifters 3b raise the laundry and water to a constant height when the spin basket 3 rotates. In order to prevent the generation of vibrations during the washing/dehydrating process, counterweights 6a,6b, each of predetermined weight, are attached to the tub 2. The front counterweight 6a is provided to the front of the tub 2, and the upper counterweight 6b is mounted on the top surface of the tub 2. The front counterweight 6a is 11.4 kg, and the upper counterweight 6b is 12.2 kg. These counterweights 6a and 6b are made from cast iron and are joined to the tub 2 by bolts 7.
Such a conventional balancing device does not prevent production of the vibrations by laundry that is not evenly distributed in the washing machine, but rather only dampens the vibrations with the counterweights attached, thus having inferior balancing characteristics. Moreover, the conventional balancing device dampens the vibrations after they have already been transmitted to the tub, and is therefore incapable of controlling an imbalance at an early stage.